Alleviation of methyl viologen-mediated oxidative stress by Brassica juncea annexin-3 in transgenic Arabidopsis

Plant annexins function as calcium-dependent or -independent phospholipid binding proteins and constitute about 0.1% of total cellular proteins. Some of them were reported to antagonize oxidative stress and protect plant cells. Brassica juncea annexin-3 (AnnBj3) was recently discovered. To gain insight into a possible function of AnnBj3 in oxidative stress response, we investigated the resistance of Arabidopsis thaliana plants expressing AnnBj3 constitutively. Here we report that, AnnBj3 attenuates methyl viologen-mediated oxidative stress in plants. It protected photosynthesis and plasma membrane from methyl viologen-mediated oxidative damage. AnnBj3 detoxifies hydrogen peroxide and showed antioxidative property in vitro. The protein increased total peroxidase activity in transgenics and interfered with other cellular antioxidants, thereby giving an overall cellular protection against methyl viologen-induced cytotoxicity.